The proposed Specialized Cooperative Center Program in Reproductive and Infertility Research (SCCPIR) is focused upon female reproductive biology with Dr. Jeffrey W. Pollard as Principal Investigator. It has evolved out of an institutional supported Center for the Study of Reproductive Biology and Women's Health founded in 2003 at the Albert Einstein College of Medicine with Dr. Pollard as Director. This Center drew together disparate strands of research in the female reproduction at the institution to form a distinct group of interactive individuals who have a translational focus. Investigators with this Center have worked for the last four years to develop this submission and in doing so have met regularly to undertake collaborative projects and used institutional funds to support clinical fellowship training relevant to the study of female reproduction. In doing so the PI's of the proposed projects have all published with one another and they have identified several fellows to be brought onto faculty to perform clinical/basic science research. The SCCPIR has four Projects (Projects 1 and 2 being clinical) and an administrative core as follows: Project 1. Dr. Jeffrey Pollard (PI) - Estrogen and Progesterone Regulation of Human Endometrial Cell Proliferation. Project 2. Dr. Nanette Santoro (PI) - Reproductive hormonal alterations in obesity. Project 3. Dr. Anne Etgen (PI) - IGF-I and Neuroendocrine Regulation of Female Reproductive Function. Project 4. Dr. Streamson Chua (PI) - Antagonistic actions of melanocortins and leptin on reproductive competence. A senior investigator leads all of these projects. There is integration amongst the projects through studies on the roles of obesity and nutrition in reproductive biology as well as the relationship between the insulin-like growth factor-1 axis and estrogen action. The PI, Dr. Jeffrey W. Pollard, is an internationally known researcher in reproductive biology having been, amongst other things, Chair of the Reproductive Tract Gordon Conference. He holds several senior administrative appointments in the College of Medicine and is well able to administer the proposed SCCPIR internally and to enable effective interactions with other SCCPIRs.